The games in many existing gaming machines, such as traditional slot machines, are based upon the concept of spinning reels. The player initiates the spin of the reels by making a wager and the positions of the reels after they stop, determines whether a player wins a value and, if so, how much value the player wins. These gaming machines typically have certain features designated for outcomes such as when a player wins a value, advances to a bonus round or when the game terminates. For example, these gaming machines often display the amount of credits earned, flash lights, make sounds or have other features designed to draw attention to the outcome and entertain the player. In one existing game when a predetermined event occurs, a wild symbol replaces various reel symbols, one at a time. If any of those replacements result in a winning combination of symbols, the player wins a certain value. U.S. Pat. No. 6,089,977 entitled, “Slot Machine Game with Roaming Wild Card,” discloses a feature generally of this type.
To increase player enjoyment and excitement, it is desirable to provide players with new features for gaming devices which use reels, where the new features involve symbols which change on the reels.